Steel Industry Shows Off Designs for Lightweight Auto Doors, Hoods, Decklids, Hatches
30 September 1998
Steel Industry Shows Off Designs for Lightweight Auto Doors, Hoods, Decklids, Hatches, Reports American Iron and Steel Institute Study Will Help Make Autos More Environmentally Benign
Designs Meet Safety, Cost, Performance Targets
DETROIT, Sept. 30 -- The world steel industry has developed a
range of design concepts for automotive doors, hoods, decklids and hatchbacks
that could save more than 50 pounds of weight in an automobile, reports
American Iron and Steel Institute. The closure concepts meet stringent
targets for safety and structural performance and could be produced using
current materials and techniques at little or no cost increase compared to
conventional closures and those made with other materials.
The concepts are the product of the UltraLight Steel Auto Closures (ULSAC)
study, a forward-looking companion to the comprehensive study of auto bodies
released in March called the UltraLight Steel Auto Body (ULSAB). The two
studies are part of the steel industry's aggressive strategy to contribute
low-cost, high-performance solutions to automakers' goal to develop and market
environmentally benign vehicles in the next decade.
The success of ULSAC's advances rely largely on design concepts featuring
thin-gauge, high and ultra high strength steels, steel sandwich panels and
burgeoning technologies including tailored blanking and hydroforming. The
designs emerged from a holistic, clean sheet approach that treats the
structure as an integrated system rather than as an assembly of individual
parts. Fundamental to the earlier ULSAB project, holistic design is a
computer-intensive, iterative process that emphasizes total structural
analysis.
The aim of holistic design strategies is to achieve highly efficient,
optimized designs. Structurally efficient designs require less mass to do
their work than less efficient structures, and as a result, contribute to
greater fuel efficiency in a vehicle. Greater fuel efficiency, in turn,
contributes to reductions in a vehicle's tailpipe emissions.
Like ULSAB, the ULSAC study provides concepts and techniques that
automakers could use immediately in their next generation vehicles and
fabricate with current and affordable materials and manufacturing processes.
As it did with ULSAB, the steel industry intends to produce demonstration
hardware to validate the study. The hardware could be ready in 2000.
An economic analysis included in the study shows that by using ULSAC
design concepts, automakers could reap steel's environmental and performance
benefits at little or no increase in cost, compared with conventional closures
and those made with other materials. A major benefit of using steel is its
relatively low cost. The analysis estimated costs of the concepts and
compared them with estimates of conventional designs. The estimates
considered materials, size, geometry and manufacturing.
Porsche Engineering Services, Inc. (PES) of Troy, Mich., conducted the
study with oversight by the steel industry's ULSAC consortium. The project
comprised benchmarking, target setting, conceptual design, finite element
analysis and cost analysis.
The benchmarking phase began with defining state-of-the-art design
concepts, based on analysis of eighteen 1997 model automobiles from around the
world. From these definitions, PES established mass, dimensions and
structural performance standards for doors, hoods, decklids and hatchbacks.
Benchmarking also served as the basis for setting dimensional, mass and
performance targets for the ULSAC designs.
Following the benchmarking phase, the consortium endorsed PES'
recommendation to pursue new approaches for three common door designs: roof-
integrated, frame-integrated and frameless. The consortium also accepted the
PES recommendations for two hood designs: conventional and grille-integrated;
and single designs for the decklid (conventional with tail type) and the
hatchback (lift-gate type).
Throughout the design process, PES conducted finite element analysis on
each part to confirm that local closure vibration modes would not coincide
with body structure modes.
American Iron and Steel Institute (AISI) is a non-profit association of
North American companies engaged in the iron and steel industry. The
Institute comprises 48 member companies, including integrated and electric
furnace steelmakers, and 173 associates and affiliate members who are
suppliers to or customers of the steel industry. For more news about steel
and its applications, view AISI's website at http://www.steel.org.
The Automotive Applications Committee (AAC) is a subcommittee of the
Market Development Committee of AISI and focuses on advancing the use of steel
in the highly competitive automotive market. With offices and staff located
in Detroit, cooperation between the automobile and steel industries has been
significant to its success. This industry cooperation resulted in the
formation of the Auto/Steel Partnership, a consortium of Chrysler, Ford and
General Motors and the member companies of the AAC.
This release and other steel-related information are available for viewing
and downloading at American Iron and Steel Institute/Automotive Applications
Committee's website at http://www.autosteel.org.
Automotive Applications Committee member companies:
AK Steel Corporation
Acme Steel Company
Bethlehem Steel Corporation
Dofasco Inc.
Inland Steel Company
LTV Steel Company
National Steel Corporation
Rouge Steel Company
Stelco Inc.
US Steel Group, a unit of USX Corporation
WCI Steel, Inc.
Weirton Steel Corporation
